Patents Examined by David Hung Vu
  • Patent number: 7550934
    Abstract: An LED driver drives one or more strings of series-connected LEDs. A feedback voltage at a sense resistor is detected by an op amp, and the op amp controls the conductivity of a MOSFET in series with the LEDs to regulate the peak current. The MOSFET is also controlled by a PWM brightness control signal to turn the LEDs on and off at the PWM duty cycle. A boost regulator provides an output voltage to the string of LEDs. A divided voltage at the end of the string of LEDs is regulated by the boost controller to keep the divided voltage constant. When an LED becomes an open circuit, the boost regulator controller is immediately decoupled from the regulator's switching transistor. If an LED shorts, the boost regulator reduces its output voltage, and the duty cycle of the brightness control signal is automatically increased.
    Type: Grant
    Filed: April 2, 2008
    Date of Patent: June 23, 2009
    Assignee: Micrel, Inc.
    Inventors: Qi Deng, Weiguang Qiu
  • Patent number: 7548030
    Abstract: A method of controlling the output of a luminaire by receiving a first target signal associated with a first frame; generating a first light output control signal for an on time portion of the first frame, the light output control signal responsive to the received first target signal; sampling a light output during the on time portion of the first frame, the light output being responsive to the first light output control signal; receiving a second target signal associated with a second frame, the second frame following the first frame; comparing the received second target signal with the sampled light output of the on time portion of the first frame; and generating an error signal responsive to the comparing.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: June 16, 2009
    Assignee: Microsemi Corp.—Analog Mixed Signal Group Ltd.
    Inventors: Dror Korcharz, Arkadiy Peker, Alon Ferentz, Tamir Langer
  • Patent number: 7545103
    Abstract: A cold-cathode tube lighting device uniformly lights multiple cold-cathode tubes using a common power source, and the cold-cathode tube lighting device is effectively downsized by using ballast capacitors. A substrate is divided into blocks as many as the cold-cathode tubes. Each of the blocks includes two conductor layers each including two foils. A first foil of a first conductor layer is connected to a common low-impedance power supply. Between the two conductor layers, first ballast capacitors are formed in areas where the first foils are overlapped, second ballast capacitors are formed in areas where the first and second foils are overlapped, and the third ballast capacitors are formed in areas where the second foils are overlapped. Second foils are connected to first electrodes of the cold-cathode tubes.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: June 9, 2009
    Assignee: Panasonic Corporation
    Inventors: Akeyuki Komatsu, Eiji Miyake, Kenji Kawataka, Toshio Manabe
  • Patent number: 7545101
    Abstract: A multi-zone daylight harvesting method and apparatus having a closed loop system utilizing a single light sensor is disclosed herein. This light control system includes an ambient light sensor connected to a detection circuit for detecting the amount of ambient light within a given zone and converting the light signal to an digital one. A control device couples to receive a predetermined rate of change for each respective zone from a storage unit along with the converted digital signal. The control device connects each zone of a plurality of electrical loads to control the power supplied to the electrical load at the predetermined corresponding rate of change and responsive to the amount of ambient light detected.
    Type: Grant
    Filed: May 5, 2006
    Date of Patent: June 9, 2009
    Assignee: Leviton Manufacturing Co., Inc.
    Inventors: Robert L. Hick, Richard A. Leinen
  • Patent number: 7541751
    Abstract: A low voltage lighting system includes a transformer having at least a primary winding and a secondary winding. The low voltage lighting system also includes one or more lighting elements and a voltage control circuit. The lighting elements are coupled to the secondary winding. The voltage control circuit is electrically coupled with the primary winding. The voltage control circuit is configured to automatically increase the voltage applied to the primary winding of the transformer in a predetermined manner from a first voltage to a second voltage over a predetermined period of time.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: June 2, 2009
    Assignee: MDL Corporation
    Inventor: Ali Vaziri
  • Patent number: 7541745
    Abstract: A fluorescent lamp assembly includes a fluorescent lamp ballast capable of detecting at least one of a plurality of input signals and generating an output signal. The output signal is associated with a power level that is based on the at least one detected input signal. The fluorescent lamp assembly also includes a fluorescent lamp capable of receiving the output signal and generating light. An intensity of the light is based on the power level associated with the output signal.
    Type: Grant
    Filed: November 21, 2007
    Date of Patent: June 2, 2009
    Assignee: STMicroelectronics, Inc.
    Inventor: Thomas L. Hopkins
  • Patent number: 7541755
    Abstract: Many applications in scientific experimentation or industrial production require the generation and shaping of charged particle bunches. A particle bunch shaper can use less expensive and smaller electrical waveform generators when the particle bunch shaper uses a nanocrystalline magnetic material. High voltage switches are examples of electrical waveform generators. A pipe with two conductive sections separated by a ceramic gap can be run through the center of cores made with the nanocrystalline magnetic material to produce the particle bunch shaper. A voltage waveform transmitted from an electrical waveform generator, through a damping circuit, and through a coupling wire running adjacent to the pipe sections can shape charged particle bunches.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: June 2, 2009
    Assignee: Universities Research Association, Inc.
    Inventors: Weiren Chou, David Wildman, Akira Takagi
  • Patent number: 7541750
    Abstract: Disclosed is a DC to DC converter, which comprises: a transforming circuit, for transforming an input voltage to an output voltage; a comparator, for comparing a reference voltage and a feedback voltage proportional to the output voltage to generate a comparing signal; a control circuit, coupled to the transforming circuit and the comparator, for controlling the transforming circuit according to the comparing signal; and a time-counting device, coupled to the control circuit, for counting the time of a specific voltage level of the comparing signal; wherein the time-counting device informs the control circuit that a load open situation occurs if the specific voltage level of the comparing signal lasts a predetermined time, then the control circuit turns off the transforming circuit.
    Type: Grant
    Filed: May 28, 2007
    Date of Patent: June 2, 2009
    Assignee: Leadtrend Technology Corp.
    Inventors: Yi-Lun Shen, Da-Chun Wei
  • Patent number: 7538499
    Abstract: The present invention provides a method and apparatus for controlling the thermal stress in lighting devices, for example light-emitting elements, that are exposed to large thermal gradients typically upon start-up, for example light-emitting elements operating in relatively cold ambient environments. The present invention provides an apparatus that can reduce this thermal stress, wherein the apparatus comprises a temperature determination mechanism for evaluating the temperature of the light-emitting elements prior to activation, and a control system to control the drive current such that it is gradually ramped up to the desired steady state peak current value, wherein the ramping of the drive current is dependent on the evaluated temperature of the light-emitting element.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: May 26, 2009
    Assignee: TIR Technology LP
    Inventor: Ian Ashdown
  • Patent number: 7538498
    Abstract: A driving circuit of a surface light source and a method of driving the same are disclosed, which is suitable for decreasing the luminance-stabilization period of time and improving the low-temperature starting properties by optimizing a starting voltage and current, the driving circuit comprising an inverter controller which feedbacks a current supplied to the surface light source, and compares the feedback current to a preset reference value, to control the current supplied to the surface light source; a temperature sensor which senses an operation temperature of the surface light source; and a driving-condition determining controller which determines operation modes of the surface light source on the basis of the temperature sensed in the temperature sensor, and varies the feedback current inputted to the inverter controller according to the operation modes of the surface light source.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: May 26, 2009
    Assignee: LG Electronics Inc.
    Inventors: Jeong Wook Hur, Hwan Woong Lee
  • Patent number: 7535181
    Abstract: A method for managing a gas discharge lamp in particular for a motor vehicle headlamp. The method is of the type which consists in controlling initial and nominal supply powers of the lamp by means of control signals during the operating phases of the lamp which comprise a start-up phase, an ignition phase and a steady-state phase. The method is wherein the control signals comprise command signals which are generated externally of the ballast and which force each of the supply powers to a value selected from a set of predetermined powers as a function of each of the phases. The method makes it possible for example to manage the different modes defined by the new regulations of the AFS type, and to optimize the service life of the lamp.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: May 19, 2009
    Assignee: Valeo Vision
    Inventors: Jean-Marc Nicolai, Marc Duarte
  • Patent number: 7531954
    Abstract: A display panel includes a light-emitting element substrate provided with a plurality of pixels that are arranged in a matrix corresponding to intersections of a plurality of scanning lines and a plurality of data lines, a light-emitting element provided at each of the pixels that is driven on the basis of image data of each of the pixels, and a power supply line pad and a data line pad that are disposed on the light-emitting element substrate in a two-dimensional manner, the power supply line pad being provided with terminals of a plurality of power supply lines that supply the power to the pixels and the data line pad being provided with terminals of the plurality of data lines.
    Type: Grant
    Filed: January 23, 2006
    Date of Patent: May 12, 2009
    Assignee: Seiko Epson Corporation
    Inventor: Tadashi Yamada
  • Patent number: 7531771
    Abstract: A reflector is so provided as to entirely cover a plurality of flash lamps arranged in parallel with one another. The reflector reflects flash light emitted from the flash lamps. A plurality of trigger electrodes needed to allow the flash lamps to discharge are so fixed to the reflector with insulating members interposed therebetween, respectively, as to be proximately opposed to the plurality of flash lamps in a one-to-one correspondence with each other. This eliminates the necessity to provide trigger wires one by one near the flash lamps during the maintenance of the apparatus, the change of lamps or the like, and it is possible to easily provide the trigger electrodes near the flash lamps only by fixing the reflector at a predetermined set position.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: May 12, 2009
    Assignee: Dainippon Screen Mfg. Co., Ltd.
    Inventor: Tatsufumi Kusuda
  • Patent number: 7528550
    Abstract: An ion implantation is disclosed that includes an ionization chamber having a restricted outlet aperture and configured so that the gas or vapor in the ionization chamber is at a pressure substantially higher than the pressure within an extraction region into which the ions are to be extracted external to the ionization chamber. The vapor is ionized by direct electron impact ionization by an electron source that is in a region adjacent the outlet aperture of the ionization chamber to produce ions from the molecules of the gas or vapor to a density of at least 1010 cm?3 at the aperture while maintaining conditions that limit the transverse kinetic energy of the ions to less than about 0.7 eV. The beam is transported to a target surface and the ions of the transported ion beam are implanted into the target.
    Type: Grant
    Filed: December 29, 2006
    Date of Patent: May 5, 2009
    Assignee: SemEquip, Inc.
    Inventors: Thomas N. Horsky, Brian C. Cohen, Wade A. Krull, George P. Sacco, Jr.
  • Patent number: 7528558
    Abstract: A ballast (10) for powering a lamp load (70) comprising one or more gas discharge lamps (72,74) includes an inverter (200), a resonant output circuit (400), and a control circuit (600). During operation of ballast (10), control circuit (600) monitors at least one voltage within one or more series resonant circuits of output circuit (400). When the monitored voltage reaches a specified level, control circuit (600) directs inverter (200) to maintain its operating frequency at a present value for a predetermined period of time, so as to allow output circuit (400) to provide a suitably high voltage for igniting the lamp(s). If the lamp(s) ignite within the predetermined period of time, control circuit (600) ceases controlling inverter (200) to maintain its operating frequency at the present value, so as to allow for normal operation of the lamp(s).
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: May 5, 2009
    Assignee: Osram Sylvania, Inc.
    Inventors: Qinghong Yu, Joseph L. Parisella
  • Patent number: 7528557
    Abstract: An electronic controller for a high-power gas discharging lamp bulb includes a filter circuit to reduce interference and control the electromagnetic characteristics of an input power signal. A rectifier circuit electrically communicates with the filter circuit to generate a DC power signal. A power factor switching circuit electrically communicates with the rectifier circuit to increase the power factor and to stabilize the voltage and current of the power signal. A driver inversion and power control circuit electrically communicates with the power factor switching circuit to adjust to loading of the controller. An initiation trigger protective circuit electrically communicates with the driver inversion and power control circuit to control the timing of passing a trigger voltage to the lamp. An output matching circuit electrically communicates with the initiation trigger protective circuit to match the impedance of the lamp bulb connected to the output matching circuit.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: May 5, 2009
    Inventor: Luoding Yang
  • Patent number: 7525257
    Abstract: A driving device for driving a light source module (32) includes a first power stage circuit (30) and a first transformer circuit (31). The first transformer circuit is connected to the first power stage circuit, including a first transformer (T31), a second transformer (T32), a third transformer (T33), and a fourth transformer (T34). First inputs of primary windings of the first transformer and the fourth transformer, second inputs of primary windings of the second transformer and the third transformer are jointly connected to a positive output of the first power stage circuit, and second inputs of primary windings of the first transformer and the fourth transformer, first inputs of primary windings of the second transformer and the third transformer are jointly connected to a negative output of the first power stage circuit.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: April 28, 2009
    Assignee: Hon Hai Precision Industry Co., Ltd.
    Inventor: Kuo-Chi Liu
  • Patent number: 7525261
    Abstract: A circuit arrangement for operating a high pressure discharge lamp comprises a down converter equipped with an output capacitor and a commutator equipped with lamp connection terminals. The amplitude of the DC current generated by the down converter is controlled by means of a control loop. Commutation of the DC current causes a periodical voltage to be present across the output capacitor. This periodical voltage can be an overshoot voltage and/or a voltage caused by resonance of the lamp with the output capacitor. To suppress the periodical voltage, the reference signal of the current control loop is adjusted in dependency of the amplitude of the periodical voltage.
    Type: Grant
    Filed: November 6, 2003
    Date of Patent: April 28, 2009
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Roy Hendrik Anna Maria Van Zundert, Thijs Oosterbaan, Dolf Henricus Jozef Van Casteren
  • Patent number: 7525253
    Abstract: A plasma lamp including a waveguide body comprising at least one dielectric material. The body is coupled to a microwave power source which causes the body to resonate in at least one resonant mode. A lamp chamber integrated with the body contains a bulb with a fill forming a light-emitting plasma when the chamber receives power from the resonating body. A bulb either is self-enclosed or an envelope sealed by a window or lens covering the chamber aperture. Embodiments disclosed include lamps having a drive probe and a feedback probe, and lamps having a drive probe, feedback probe and start probe, which minimize power reflected from the body back to the source.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: April 28, 2009
    Assignee: Luxim Corporation
    Inventors: Frederick M. Espiau, Yian Chang
  • Patent number: 7525254
    Abstract: Vehicle lighting methods and apparatus, in which an LED-based light source is configured to generate at least visible radiation associated with a vehicle. The light source is controlled such that the generated visible radiation has a variable color over a range of colors including at least three different perceivable colors. Examples of vehicles in which such methods and apparatus may be used include, but are not limited to, an automobile, airplane, boat, non-motorized vehicle, etc. The LED-based light source may be disposed inside the vehicle (e.g., dashboard, instrument panel) or outside the vehicle (e.g., brake lights, undercarriage lighting), and may be controlled to generate white light as one of the perceivable colors. A user interface may be employed to facilitate an adjustment of the variable color of the generated visible radiation.
    Type: Grant
    Filed: November 3, 2004
    Date of Patent: April 28, 2009
    Assignee: Philips Solid-State Lighting Solutions, Inc.
    Inventors: Ihor Lys, George G. Mueller